git.oblomov.eu Git - git/blob - builtin/index-pack.c

   1 #include "builtin.h"
   2 #include "delta.h"
   3 #include "pack.h"
   4 #include "csum-file.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "progress.h"
  10 #include "fsck.h"
  11 #include "exec_cmd.h"
  12 #include "thread-utils.h"
  13
  14 static const char index_pack_usage[] =
  15 "git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  16
  17 struct object_entry {
  18         struct pack_idx_entry idx;
  19         unsigned long size;
  20         unsigned int hdr_size;
  21         enum object_type type;
  22         enum object_type real_type;
  23         unsigned delta_depth;
  24         int base_object_no;
  25 };
  26
  27 union delta_base {
  28         unsigned char sha1[20];
  29         off_t offset;
  30 };
  31
  32 struct base_data {
  33         struct base_data *base;
  34         struct base_data *child;
  35         struct object_entry *obj;
  36         void *data;
  37         unsigned long size;
  38         int ref_first, ref_last;
  39         int ofs_first, ofs_last;
  40 };
  41
  42 #if !defined(NO_PTHREADS) && defined(NO_PREAD)
  43 /* NO_PREAD uses compat/pread.c, which is not thread-safe. Disable threading. */
  44 #define NO_PTHREADS
  45 #endif
  46
  47 struct thread_local {
  48 #ifndef NO_PTHREADS
  49         pthread_t thread;
  50 #endif
  51         struct base_data *base_cache;
  52         size_t base_cache_used;
  53 };
  54
  55 /*
  56  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  57  * to memcmp() only the first 20 bytes.
  58  */
  59 #define UNION_BASE_SZ   20
  60
  61 #define FLAG_LINK (1u<<20)
  62 #define FLAG_CHECKED (1u<<21)
  63
  64 struct delta_entry {
  65         union delta_base base;
  66         int obj_no;
  67 };
  68
  69 static struct object_entry *objects;
  70 static struct delta_entry *deltas;
  71 static struct thread_local nothread_data;
  72 static int nr_objects;
  73 static int nr_deltas;
  74 static int nr_resolved_deltas;
  75 static int nr_threads;
  76
  77 static int from_stdin;
  78 static int strict;
  79 static int verbose;
  80
  81 static struct progress *progress;
  82
  83 /* We always read in 4kB chunks. */
  84 static unsigned char input_buffer[4096];
  85 static unsigned int input_offset, input_len;
  86 static off_t consumed_bytes;
  87 static unsigned deepest_delta;
  88 static git_SHA_CTX input_ctx;
  89 static uint32_t input_crc32;
  90 static int input_fd, output_fd, pack_fd;
  91
  92 #ifndef NO_PTHREADS
  93
  94 static struct thread_local *thread_data;
  95 static int nr_dispatched;
  96 static int threads_active;
  97
  98 static pthread_mutex_t read_mutex;
  99 #define read_lock()             lock_mutex(&read_mutex)
 100 #define read_unlock()           unlock_mutex(&read_mutex)
 101
 102 static pthread_mutex_t counter_mutex;
 103 #define counter_lock()          lock_mutex(&counter_mutex)
 104 #define counter_unlock()        unlock_mutex(&counter_mutex)
 105
 106 static pthread_mutex_t work_mutex;
 107 #define work_lock()             lock_mutex(&work_mutex)
 108 #define work_unlock()           unlock_mutex(&work_mutex)
 109
 110 static pthread_key_t key;
 111
 112 static inline void lock_mutex(pthread_mutex_t *mutex)
 113 {
 114         if (threads_active)
 115                 pthread_mutex_lock(mutex);
 116 }
 117
 118 static inline void unlock_mutex(pthread_mutex_t *mutex)
 119 {
 120         if (threads_active)
 121                 pthread_mutex_unlock(mutex);
 122 }
 123
 124 /*
 125  * Mutex and conditional variable can't be statically-initialized on Windows.
 126  */
 127 static void init_thread(void)
 128 {
 129         init_recursive_mutex(&read_mutex);
 130         pthread_mutex_init(&counter_mutex, NULL);
 131         pthread_mutex_init(&work_mutex, NULL);
 132         pthread_key_create(&key, NULL);
 133         thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 134         threads_active = 1;
 135 }
 136
 137 static void cleanup_thread(void)
 138 {
 139         if (!threads_active)
 140                 return;
 141         threads_active = 0;
 142         pthread_mutex_destroy(&read_mutex);
 143         pthread_mutex_destroy(&counter_mutex);
 144         pthread_mutex_destroy(&work_mutex);
 145         pthread_key_delete(key);
 146         free(thread_data);
 147 }
 148
 149 #else
 150
 151 #define read_lock()
 152 #define read_unlock()
 153
 154 #define counter_lock()
 155 #define counter_unlock()
 156
 157 #define work_lock()
 158 #define work_unlock()
 159
 160 #endif
 161
 162
 163 static int mark_link(struct object *obj, int type, void *data)
 164 {
 165         if (!obj)
 166                 return -1;
 167
 168         if (type != OBJ_ANY && obj->type != type)
 169                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
 170
 171         obj->flags |= FLAG_LINK;
 172         return 0;
 173 }
 174
 175 /* The content of each linked object must have been checked
 176    or it must be already present in the object database */
 177 static void check_object(struct object *obj)
 178 {
 179         if (!obj)
 180                 return;
 181
 182         if (!(obj->flags & FLAG_LINK))
 183                 return;
 184
 185         if (!(obj->flags & FLAG_CHECKED)) {
 186                 unsigned long size;
 187                 int type = sha1_object_info(obj->sha1, &size);
 188                 if (type != obj->type || type <= 0)
 189                         die("object of unexpected type");
 190                 obj->flags |= FLAG_CHECKED;
 191                 return;
 192         }
 193 }
 194
 195 static void check_objects(void)
 196 {
 197         unsigned i, max;
 198
 199         max = get_max_object_index();
 200         for (i = 0; i < max; i++)
 201                 check_object(get_indexed_object(i));
 202 }
 203
 204
 205 /* Discard current buffer used content. */
 206 static void flush(void)
 207 {
 208         if (input_offset) {
 209                 if (output_fd >= 0)
 210                         write_or_die(output_fd, input_buffer, input_offset);
 211                 git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 212                 memmove(input_buffer, input_buffer + input_offset, input_len);
 213                 input_offset = 0;
 214         }
 215 }
 216
 217 /*
 218  * Make sure at least "min" bytes are available in the buffer, and
 219  * return the pointer to the buffer.
 220  */
 221 static void *fill(int min)
 222 {
 223         if (min <= input_len)
 224                 return input_buffer + input_offset;
 225         if (min > sizeof(input_buffer))
 226                 die("cannot fill %d bytes", min);
 227         flush();
 228         do {
 229                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 230                                 sizeof(input_buffer) - input_len);
 231                 if (ret <= 0) {
 232                         if (!ret)
 233                                 die("early EOF");
 234                         die_errno("read error on input");
 235                 }
 236                 input_len += ret;
 237                 if (from_stdin)
 238                         display_throughput(progress, consumed_bytes + input_len);
 239         } while (input_len < min);
 240         return input_buffer;
 241 }
 242
 243 static void use(int bytes)
 244 {
 245         if (bytes > input_len)
 246                 die("used more bytes than were available");
 247         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 248         input_len -= bytes;
 249         input_offset += bytes;
 250
 251         /* make sure off_t is sufficiently large not to wrap */
 252         if (signed_add_overflows(consumed_bytes, bytes))
 253                 die("pack too large for current definition of off_t");
 254         consumed_bytes += bytes;
 255 }
 256
 257 static const char *open_pack_file(const char *pack_name)
 258 {
 259         if (from_stdin) {
 260                 input_fd = 0;
 261                 if (!pack_name) {
 262                         static char tmp_file[PATH_MAX];
 263                         output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 264                                                 "pack/tmp_pack_XXXXXX");
 265                         pack_name = xstrdup(tmp_file);
 266                 } else
 267                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 268                 if (output_fd < 0)
 269                         die_errno("unable to create '%s'", pack_name);
 270                 pack_fd = output_fd;
 271         } else {
 272                 input_fd = open(pack_name, O_RDONLY);
 273                 if (input_fd < 0)
 274                         die_errno("cannot open packfile '%s'", pack_name);
 275                 output_fd = -1;
 276                 pack_fd = input_fd;
 277         }
 278         git_SHA1_Init(&input_ctx);
 279         return pack_name;
 280 }
 281
 282 static void parse_pack_header(void)
 283 {
 284         struct pack_header *hdr = fill(sizeof(struct pack_header));
 285
 286         /* Header consistency check */
 287         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 288                 die("pack signature mismatch");
 289         if (!pack_version_ok(hdr->hdr_version))
 290                 die("pack version %"PRIu32" unsupported",
 291                         ntohl(hdr->hdr_version));
 292
 293         nr_objects = ntohl(hdr->hdr_entries);
 294         use(sizeof(struct pack_header));
 295 }
 296
 297 static NORETURN void bad_object(unsigned long offset, const char *format,
 298                        ...) __attribute__((format (printf, 2, 3)));
 299
 300 static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 301 {
 302         va_list params;
 303         char buf[1024];
 304
 305         va_start(params, format);
 306         vsnprintf(buf, sizeof(buf), format, params);
 307         va_end(params);
 308         die("pack has bad object at offset %lu: %s", offset, buf);
 309 }
 310
 311 static inline struct thread_local *get_thread_data(void)
 312 {
 313 #ifndef NO_PTHREADS
 314         if (threads_active)
 315                 return pthread_getspecific(key);
 316         assert(!threads_active &&
 317                "This should only be reached when all threads are gone");
 318 #endif
 319         return &nothread_data;
 320 }
 321
 322 #ifndef NO_PTHREADS
 323 static void set_thread_data(struct thread_local *data)
 324 {
 325         if (threads_active)
 326                 pthread_setspecific(key, data);
 327 }
 328 #endif
 329
 330 static struct base_data *alloc_base_data(void)
 331 {
 332         struct base_data *base = xmalloc(sizeof(struct base_data));
 333         memset(base, 0, sizeof(*base));
 334         base->ref_last = -1;
 335         base->ofs_last = -1;
 336         return base;
 337 }
 338
 339 static void free_base_data(struct base_data *c)
 340 {
 341         if (c->data) {
 342                 free(c->data);
 343                 c->data = NULL;
 344                 get_thread_data()->base_cache_used -= c->size;
 345         }
 346 }
 347
 348 static void prune_base_data(struct base_data *retain)
 349 {
 350         struct base_data *b;
 351         struct thread_local *data = get_thread_data();
 352         for (b = data->base_cache;
 353              data->base_cache_used > delta_base_cache_limit && b;
 354              b = b->child) {
 355                 if (b->data && b != retain)
 356                         free_base_data(b);
 357         }
 358 }
 359
 360 static void link_base_data(struct base_data *base, struct base_data *c)
 361 {
 362         if (base)
 363                 base->child = c;
 364         else
 365                 get_thread_data()->base_cache = c;
 366
 367         c->base = base;
 368         c->child = NULL;
 369         if (c->data)
 370                 get_thread_data()->base_cache_used += c->size;
 371         prune_base_data(c);
 372 }
 373
 374 static void unlink_base_data(struct base_data *c)
 375 {
 376         struct base_data *base = c->base;
 377         if (base)
 378                 base->child = NULL;
 379         else
 380                 get_thread_data()->base_cache = NULL;
 381         free_base_data(c);
 382 }
 383
 384 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 385 {
 386         int status;
 387         git_zstream stream;
 388         void *buf = xmalloc(size);
 389
 390         memset(&stream, 0, sizeof(stream));
 391         git_inflate_init(&stream);
 392         stream.next_out = buf;
 393         stream.avail_out = size;
 394
 395         do {
 396                 stream.next_in = fill(1);
 397                 stream.avail_in = input_len;
 398                 status = git_inflate(&stream, 0);
 399                 use(input_len - stream.avail_in);
 400         } while (status == Z_OK);
 401         if (stream.total_out != size || status != Z_STREAM_END)
 402                 bad_object(offset, "inflate returned %d", status);
 403         git_inflate_end(&stream);
 404         return buf;
 405 }
 406
 407 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 408 {
 409         unsigned char *p;
 410         unsigned long size, c;
 411         off_t base_offset;
 412         unsigned shift;
 413         void *data;
 414
 415         obj->idx.offset = consumed_bytes;
 416         input_crc32 = crc32(0, NULL, 0);
 417
 418         p = fill(1);
 419         c = *p;
 420         use(1);
 421         obj->type = (c >> 4) & 7;
 422         size = (c & 15);
 423         shift = 4;
 424         while (c & 0x80) {
 425                 p = fill(1);
 426                 c = *p;
 427                 use(1);
 428                 size += (c & 0x7f) << shift;
 429                 shift += 7;
 430         }
 431         obj->size = size;
 432
 433         switch (obj->type) {
 434         case OBJ_REF_DELTA:
 435                 hashcpy(delta_base->sha1, fill(20));
 436                 use(20);
 437                 break;
 438         case OBJ_OFS_DELTA:
 439                 memset(delta_base, 0, sizeof(*delta_base));
 440                 p = fill(1);
 441                 c = *p;
 442                 use(1);
 443                 base_offset = c & 127;
 444                 while (c & 128) {
 445                         base_offset += 1;
 446                         if (!base_offset || MSB(base_offset, 7))
 447                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 448                         p = fill(1);
 449                         c = *p;
 450                         use(1);
 451                         base_offset = (base_offset << 7) + (c & 127);
 452                 }
 453                 delta_base->offset = obj->idx.offset - base_offset;
 454                 if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 455                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 456                 break;
 457         case OBJ_COMMIT:
 458         case OBJ_TREE:
 459         case OBJ_BLOB:
 460         case OBJ_TAG:
 461                 break;
 462         default:
 463                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 464         }
 465         obj->hdr_size = consumed_bytes - obj->idx.offset;
 466
 467         data = unpack_entry_data(obj->idx.offset, obj->size);
 468         obj->idx.crc32 = input_crc32;
 469         return data;
 470 }
 471
 472 static void *get_data_from_pack(struct object_entry *obj)
 473 {
 474         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 475         unsigned long len = obj[1].idx.offset - from;
 476         unsigned char *data, *inbuf;
 477         git_zstream stream;
 478         int status;
 479
 480         data = xmalloc(obj->size);
 481         inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 482
 483         memset(&stream, 0, sizeof(stream));
 484         git_inflate_init(&stream);
 485         stream.next_out = data;
 486         stream.avail_out = obj->size;
 487
 488         do {
 489                 ssize_t n = (len < 64*1024) ? len : 64*1024;
 490                 n = pread(pack_fd, inbuf, n, from);
 491                 if (n < 0)
 492                         die_errno("cannot pread pack file");
 493                 if (!n)
 494                         die("premature end of pack file, %lu bytes missing", len);
 495                 from += n;
 496                 len -= n;
 497                 stream.next_in = inbuf;
 498                 stream.avail_in = n;
 499                 status = git_inflate(&stream, 0);
 500         } while (len && status == Z_OK && !stream.avail_in);
 501
 502         /* This has been inflated OK when first encountered, so... */
 503         if (status != Z_STREAM_END || stream.total_out != obj->size)
 504                 die("serious inflate inconsistency");
 505
 506         git_inflate_end(&stream);
 507         free(inbuf);
 508         return data;
 509 }
 510
 511 static int compare_delta_bases(const union delta_base *base1,
 512                                const union delta_base *base2,
 513                                enum object_type type1,
 514                                enum object_type type2)
 515 {
 516         int cmp = type1 - type2;
 517         if (cmp)
 518                 return cmp;
 519         return memcmp(base1, base2, UNION_BASE_SZ);
 520 }
 521
 522 static int find_delta(const union delta_base *base, enum object_type type)
 523 {
 524         int first = 0, last = nr_deltas;
 525
 526         while (first < last) {
 527                 int next = (first + last) / 2;
 528                 struct delta_entry *delta = &deltas[next];
 529                 int cmp;
 530
 531                 cmp = compare_delta_bases(base, &delta->base,
 532                                           type, objects[delta->obj_no].type);
 533                 if (!cmp)
 534                         return next;
 535                 if (cmp < 0) {
 536                         last = next;
 537                         continue;
 538                 }
 539                 first = next+1;
 540         }
 541         return -first-1;
 542 }
 543
 544 static void find_delta_children(const union delta_base *base,
 545                                 int *first_index, int *last_index,
 546                                 enum object_type type)
 547 {
 548         int first = find_delta(base, type);
 549         int last = first;
 550         int end = nr_deltas - 1;
 551
 552         if (first < 0) {
 553                 *first_index = 0;
 554                 *last_index = -1;
 555                 return;
 556         }
 557         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 558                 --first;
 559         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 560                 ++last;
 561         *first_index = first;
 562         *last_index = last;
 563 }
 564
 565 static void sha1_object(const void *data, unsigned long size,
 566                         enum object_type type, unsigned char *sha1)
 567 {
 568         hash_sha1_file(data, size, typename(type), sha1);
 569         read_lock();
 570         if (has_sha1_file(sha1)) {
 571                 void *has_data;
 572                 enum object_type has_type;
 573                 unsigned long has_size;
 574                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 575                 read_unlock();
 576                 if (!has_data)
 577                         die("cannot read existing object %s", sha1_to_hex(sha1));
 578                 if (size != has_size || type != has_type ||
 579                     memcmp(data, has_data, size) != 0)
 580                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 581                 free(has_data);
 582         } else
 583                 read_unlock();
 584
 585         if (strict) {
 586                 read_lock();
 587                 if (type == OBJ_BLOB) {
 588                         struct blob *blob = lookup_blob(sha1);
 589                         if (blob)
 590                                 blob->object.flags |= FLAG_CHECKED;
 591                         else
 592                                 die("invalid blob object %s", sha1_to_hex(sha1));
 593                 } else {
 594                         struct object *obj;
 595                         int eaten;
 596                         void *buf = (void *) data;
 597
 598                         /*
 599                          * we do not need to free the memory here, as the
 600                          * buf is deleted by the caller.
 601                          */
 602                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 603                         if (!obj)
 604                                 die("invalid %s", typename(type));
 605                         if (fsck_object(obj, 1, fsck_error_function))
 606                                 die("Error in object");
 607                         if (fsck_walk(obj, mark_link, NULL))
 608                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 609
 610                         if (obj->type == OBJ_TREE) {
 611                                 struct tree *item = (struct tree *) obj;
 612                                 item->buffer = NULL;
 613                         }
 614                         if (obj->type == OBJ_COMMIT) {
 615                                 struct commit *commit = (struct commit *) obj;
 616                                 commit->buffer = NULL;
 617                         }
 618                         obj->flags |= FLAG_CHECKED;
 619                 }
 620                 read_unlock();
 621         }
 622 }
 623
 624 static int is_delta_type(enum object_type type)
 625 {
 626         return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 627 }
 628
 629 /*
 630  * This function is part of find_unresolved_deltas(). There are two
 631  * walkers going in the opposite ways.
 632  *
 633  * The first one in find_unresolved_deltas() traverses down from
 634  * parent node to children, deflating nodes along the way. However,
 635  * memory for deflated nodes is limited by delta_base_cache_limit, so
 636  * at some point parent node's deflated content may be freed.
 637  *
 638  * The second walker is this function, which goes from current node up
 639  * to top parent if necessary to deflate the node. In normal
 640  * situation, its parent node would be already deflated, so it just
 641  * needs to apply delta.
 642  *
 643  * In the worst case scenario, parent node is no longer deflated because
 644  * we're running out of delta_base_cache_limit; we need to re-deflate
 645  * parents, possibly up to the top base.
 646  *
 647  * All deflated objects here are subject to be freed if we exceed
 648  * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 649  * just need to make sure the last node is not freed.
 650  */
 651 static void *get_base_data(struct base_data *c)
 652 {
 653         if (!c->data) {
 654                 struct object_entry *obj = c->obj;
 655                 struct base_data **delta = NULL;
 656                 int delta_nr = 0, delta_alloc = 0;
 657
 658                 while (is_delta_type(c->obj->type) && !c->data) {
 659                         ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 660                         delta[delta_nr++] = c;
 661                         c = c->base;
 662                 }
 663                 if (!delta_nr) {
 664                         c->data = get_data_from_pack(obj);
 665                         c->size = obj->size;
 666                         get_thread_data()->base_cache_used += c->size;
 667                         prune_base_data(c);
 668                 }
 669                 for (; delta_nr > 0; delta_nr--) {
 670                         void *base, *raw;
 671                         c = delta[delta_nr - 1];
 672                         obj = c->obj;
 673                         base = get_base_data(c->base);
 674                         raw = get_data_from_pack(obj);
 675                         c->data = patch_delta(
 676                                 base, c->base->size,
 677                                 raw, obj->size,
 678                                 &c->size);
 679                         free(raw);
 680                         if (!c->data)
 681                                 bad_object(obj->idx.offset, "failed to apply delta");
 682                         get_thread_data()->base_cache_used += c->size;
 683                         prune_base_data(c);
 684                 }
 685                 free(delta);
 686         }
 687         return c->data;
 688 }
 689
 690 static void resolve_delta(struct object_entry *delta_obj,
 691                           struct base_data *base, struct base_data *result)
 692 {
 693         void *base_data, *delta_data;
 694
 695         delta_obj->real_type = base->obj->real_type;
 696         delta_obj->delta_depth = base->obj->delta_depth + 1;
 697         if (deepest_delta < delta_obj->delta_depth)
 698                 deepest_delta = delta_obj->delta_depth;
 699         delta_obj->base_object_no = base->obj - objects;
 700         delta_data = get_data_from_pack(delta_obj);
 701         base_data = get_base_data(base);
 702         result->obj = delta_obj;
 703         result->data = patch_delta(base_data, base->size,
 704                                    delta_data, delta_obj->size, &result->size);
 705         free(delta_data);
 706         if (!result->data)
 707                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 708         sha1_object(result->data, result->size, delta_obj->real_type,
 709                     delta_obj->idx.sha1);
 710         counter_lock();
 711         nr_resolved_deltas++;
 712         counter_unlock();
 713 }
 714
 715 static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 716                                                   struct base_data *prev_base)
 717 {
 718         if (base->ref_last == -1 && base->ofs_last == -1) {
 719                 union delta_base base_spec;
 720
 721                 hashcpy(base_spec.sha1, base->obj->idx.sha1);
 722                 find_delta_children(&base_spec,
 723                                     &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 724
 725                 memset(&base_spec, 0, sizeof(base_spec));
 726                 base_spec.offset = base->obj->idx.offset;
 727                 find_delta_children(&base_spec,
 728                                     &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 729
 730                 if (base->ref_last == -1 && base->ofs_last == -1) {
 731                         free(base->data);
 732                         return NULL;
 733                 }
 734
 735                 link_base_data(prev_base, base);
 736         }
 737
 738         if (base->ref_first <= base->ref_last) {
 739                 struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 740                 struct base_data *result = alloc_base_data();
 741
 742                 assert(child->real_type == OBJ_REF_DELTA);
 743                 resolve_delta(child, base, result);
 744                 if (base->ref_first == base->ref_last && base->ofs_last == -1)
 745                         free_base_data(base);
 746
 747                 base->ref_first++;
 748                 return result;
 749         }
 750
 751         if (base->ofs_first <= base->ofs_last) {
 752                 struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 753                 struct base_data *result = alloc_base_data();
 754
 755                 assert(child->real_type == OBJ_OFS_DELTA);
 756                 resolve_delta(child, base, result);
 757                 if (base->ofs_first == base->ofs_last)
 758                         free_base_data(base);
 759
 760                 base->ofs_first++;
 761                 return result;
 762         }
 763
 764         unlink_base_data(base);
 765         return NULL;
 766 }
 767
 768 static void find_unresolved_deltas(struct base_data *base)
 769 {
 770         struct base_data *new_base, *prev_base = NULL;
 771         for (;;) {
 772                 new_base = find_unresolved_deltas_1(base, prev_base);
 773
 774                 if (new_base) {
 775                         prev_base = base;
 776                         base = new_base;
 777                 } else {
 778                         free(base);
 779                         base = prev_base;
 780                         if (!base)
 781                                 return;
 782                         prev_base = base->base;
 783                 }
 784         }
 785 }
 786
 787 static int compare_delta_entry(const void *a, const void *b)
 788 {
 789         const struct delta_entry *delta_a = a;
 790         const struct delta_entry *delta_b = b;
 791
 792         /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 793         return compare_delta_bases(&delta_a->base, &delta_b->base,
 794                                    objects[delta_a->obj_no].type,
 795                                    objects[delta_b->obj_no].type);
 796 }
 797
 798 static void resolve_base(struct object_entry *obj)
 799 {
 800         struct base_data *base_obj = alloc_base_data();
 801         base_obj->obj = obj;
 802         base_obj->data = NULL;
 803         find_unresolved_deltas(base_obj);
 804 }
 805
 806 #ifndef NO_PTHREADS
 807 static void *threaded_second_pass(void *data)
 808 {
 809         set_thread_data(data);
 810         for (;;) {
 811                 int i;
 812                 work_lock();
 813                 display_progress(progress, nr_resolved_deltas);
 814                 while (nr_dispatched < nr_objects &&
 815                        is_delta_type(objects[nr_dispatched].type))
 816                         nr_dispatched++;
 817                 if (nr_dispatched >= nr_objects) {
 818                         work_unlock();
 819                         break;
 820                 }
 821                 i = nr_dispatched++;
 822                 work_unlock();
 823
 824                 resolve_base(&objects[i]);
 825         }
 826         return NULL;
 827 }
 828 #endif
 829
 830 /*
 831  * First pass:
 832  * - find locations of all objects;
 833  * - calculate SHA1 of all non-delta objects;
 834  * - remember base (SHA1 or offset) for all deltas.
 835  */
 836 static void parse_pack_objects(unsigned char *sha1)
 837 {
 838         int i;
 839         struct delta_entry *delta = deltas;
 840         struct stat st;
 841
 842         if (verbose)
 843                 progress = start_progress(
 844                                 from_stdin ? "Receiving objects" : "Indexing objects",
 845                                 nr_objects);
 846         for (i = 0; i < nr_objects; i++) {
 847                 struct object_entry *obj = &objects[i];
 848                 void *data = unpack_raw_entry(obj, &delta->base);
 849                 obj->real_type = obj->type;
 850                 if (is_delta_type(obj->type)) {
 851                         nr_deltas++;
 852                         delta->obj_no = i;
 853                         delta++;
 854                 } else
 855                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 856                 free(data);
 857                 display_progress(progress, i+1);
 858         }
 859         objects[i].idx.offset = consumed_bytes;
 860         stop_progress(&progress);
 861
 862         /* Check pack integrity */
 863         flush();
 864         git_SHA1_Final(sha1, &input_ctx);
 865         if (hashcmp(fill(20), sha1))
 866                 die("pack is corrupted (SHA1 mismatch)");
 867         use(20);
 868
 869         /* If input_fd is a file, we should have reached its end now. */
 870         if (fstat(input_fd, &st))
 871                 die_errno("cannot fstat packfile");
 872         if (S_ISREG(st.st_mode) &&
 873                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 874                 die("pack has junk at the end");
 875 }
 876
 877 /*
 878  * Second pass:
 879  * - for all non-delta objects, look if it is used as a base for
 880  *   deltas;
 881  * - if used as a base, uncompress the object and apply all deltas,
 882  *   recursively checking if the resulting object is used as a base
 883  *   for some more deltas.
 884  */
 885 static void resolve_deltas(void)
 886 {
 887         int i;
 888
 889         if (!nr_deltas)
 890                 return;
 891
 892         /* Sort deltas by base SHA1/offset for fast searching */
 893         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 894               compare_delta_entry);
 895
 896         if (verbose)
 897                 progress = start_progress("Resolving deltas", nr_deltas);
 898
 899 #ifndef NO_PTHREADS
 900         nr_dispatched = 0;
 901         if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
 902                 init_thread();
 903                 for (i = 0; i < nr_threads; i++) {
 904                         int ret = pthread_create(&thread_data[i].thread, NULL,
 905                                                  threaded_second_pass, thread_data + i);
 906                         if (ret)
 907                                 die("unable to create thread: %s", strerror(ret));
 908                 }
 909                 for (i = 0; i < nr_threads; i++)
 910                         pthread_join(thread_data[i].thread, NULL);
 911                 cleanup_thread();
 912                 return;
 913         }
 914 #endif
 915
 916         for (i = 0; i < nr_objects; i++) {
 917                 struct object_entry *obj = &objects[i];
 918
 919                 if (is_delta_type(obj->type))
 920                         continue;
 921                 resolve_base(obj);
 922                 display_progress(progress, nr_resolved_deltas);
 923         }
 924 }
 925
 926 /*
 927  * Third pass:
 928  * - append objects to convert thin pack to full pack if required
 929  * - write the final 20-byte SHA-1
 930  */
 931 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
 932 static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
 933 {
 934         if (nr_deltas == nr_resolved_deltas) {
 935                 stop_progress(&progress);
 936                 /* Flush remaining pack final 20-byte SHA1. */
 937                 flush();
 938                 return;
 939         }
 940
 941         if (fix_thin_pack) {
 942                 struct sha1file *f;
 943                 unsigned char read_sha1[20], tail_sha1[20];
 944                 char msg[48];
 945                 int nr_unresolved = nr_deltas - nr_resolved_deltas;
 946                 int nr_objects_initial = nr_objects;
 947                 if (nr_unresolved <= 0)
 948                         die("confusion beyond insanity");
 949                 objects = xrealloc(objects,
 950                                    (nr_objects + nr_unresolved + 1)
 951                                    * sizeof(*objects));
 952                 f = sha1fd(output_fd, curr_pack);
 953                 fix_unresolved_deltas(f, nr_unresolved);
 954                 sprintf(msg, "completed with %d local objects",
 955                         nr_objects - nr_objects_initial);
 956                 stop_progress_msg(&progress, msg);
 957                 sha1close(f, tail_sha1, 0);
 958                 hashcpy(read_sha1, pack_sha1);
 959                 fixup_pack_header_footer(output_fd, pack_sha1,
 960                                          curr_pack, nr_objects,
 961                                          read_sha1, consumed_bytes-20);
 962                 if (hashcmp(read_sha1, tail_sha1) != 0)
 963                         die("Unexpected tail checksum for %s "
 964                             "(disk corruption?)", curr_pack);
 965         }
 966         if (nr_deltas != nr_resolved_deltas)
 967                 die("pack has %d unresolved deltas",
 968                     nr_deltas - nr_resolved_deltas);
 969 }
 970
 971 static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 972 {
 973         git_zstream stream;
 974         int status;
 975         unsigned char outbuf[4096];
 976
 977         memset(&stream, 0, sizeof(stream));
 978         git_deflate_init(&stream, zlib_compression_level);
 979         stream.next_in = in;
 980         stream.avail_in = size;
 981
 982         do {
 983                 stream.next_out = outbuf;
 984                 stream.avail_out = sizeof(outbuf);
 985                 status = git_deflate(&stream, Z_FINISH);
 986                 sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
 987         } while (status == Z_OK);
 988
 989         if (status != Z_STREAM_END)
 990                 die("unable to deflate appended object (%d)", status);
 991         size = stream.total_out;
 992         git_deflate_end(&stream);
 993         return size;
 994 }
 995
 996 static struct object_entry *append_obj_to_pack(struct sha1file *f,
 997                                const unsigned char *sha1, void *buf,
 998                                unsigned long size, enum object_type type)
 999 {
1000         struct object_entry *obj = &objects[nr_objects++];
1001         unsigned char header[10];
1002         unsigned long s = size;
1003         int n = 0;
1004         unsigned char c = (type << 4) | (s & 15);
1005         s >>= 4;
1006         while (s) {
1007                 header[n++] = c | 0x80;
1008                 c = s & 0x7f;
1009                 s >>= 7;
1010         }
1011         header[n++] = c;
1012         crc32_begin(f);
1013         sha1write(f, header, n);
1014         obj[0].size = size;
1015         obj[0].hdr_size = n;
1016         obj[0].type = type;
1017         obj[0].real_type = type;
1018         obj[1].idx.offset = obj[0].idx.offset + n;
1019         obj[1].idx.offset += write_compressed(f, buf, size);
1020         obj[0].idx.crc32 = crc32_end(f);
1021         sha1flush(f);
1022         hashcpy(obj->idx.sha1, sha1);
1023         return obj;
1024 }
1025
1026 static int delta_pos_compare(const void *_a, const void *_b)
1027 {
1028         struct delta_entry *a = *(struct delta_entry **)_a;
1029         struct delta_entry *b = *(struct delta_entry **)_b;
1030         return a->obj_no - b->obj_no;
1031 }
1032
1033 static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1034 {
1035         struct delta_entry **sorted_by_pos;
1036         int i, n = 0;
1037
1038         /*
1039          * Since many unresolved deltas may well be themselves base objects
1040          * for more unresolved deltas, we really want to include the
1041          * smallest number of base objects that would cover as much delta
1042          * as possible by picking the
1043          * trunc deltas first, allowing for other deltas to resolve without
1044          * additional base objects.  Since most base objects are to be found
1045          * before deltas depending on them, a good heuristic is to start
1046          * resolving deltas in the same order as their position in the pack.
1047          */
1048         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1049         for (i = 0; i < nr_deltas; i++) {
1050                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1051                         continue;
1052                 sorted_by_pos[n++] = &deltas[i];
1053         }
1054         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1055
1056         for (i = 0; i < n; i++) {
1057                 struct delta_entry *d = sorted_by_pos[i];
1058                 enum object_type type;
1059                 struct base_data *base_obj = alloc_base_data();
1060
1061                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1062                         continue;
1063                 base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1064                 if (!base_obj->data)
1065                         continue;
1066
1067                 if (check_sha1_signature(d->base.sha1, base_obj->data,
1068                                 base_obj->size, typename(type)))
1069                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
1070                 base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1071                                         base_obj->data, base_obj->size, type);
1072                 find_unresolved_deltas(base_obj);
1073                 display_progress(progress, nr_resolved_deltas);
1074         }
1075         free(sorted_by_pos);
1076 }
1077
1078 static void final(const char *final_pack_name, const char *curr_pack_name,
1079                   const char *final_index_name, const char *curr_index_name,
1080                   const char *keep_name, const char *keep_msg,
1081                   unsigned char *sha1)
1082 {
1083         const char *report = "pack";
1084         char name[PATH_MAX];
1085         int err;
1086
1087         if (!from_stdin) {
1088                 close(input_fd);
1089         } else {
1090                 fsync_or_die(output_fd, curr_pack_name);
1091                 err = close(output_fd);
1092                 if (err)
1093                         die_errno("error while closing pack file");
1094         }
1095
1096         if (keep_msg) {
1097                 int keep_fd, keep_msg_len = strlen(keep_msg);
1098
1099                 if (!keep_name)
1100                         keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1101                 else
1102                         keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1103
1104                 if (keep_fd < 0) {
1105                         if (errno != EEXIST)
1106                                 die_errno("cannot write keep file '%s'",
1107                                           keep_name);
1108                 } else {
1109                         if (keep_msg_len > 0) {
1110                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
1111                                 write_or_die(keep_fd, "\n", 1);
1112                         }
1113                         if (close(keep_fd) != 0)
1114                                 die_errno("cannot close written keep file '%s'",
1115                                     keep_name);
1116                         report = "keep";
1117                 }
1118         }
1119
1120         if (final_pack_name != curr_pack_name) {
1121                 if (!final_pack_name) {
1122                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1123                                  get_object_directory(), sha1_to_hex(sha1));
1124                         final_pack_name = name;
1125                 }
1126                 if (move_temp_to_file(curr_pack_name, final_pack_name))
1127                         die("cannot store pack file");
1128         } else if (from_stdin)
1129                 chmod(final_pack_name, 0444);
1130
1131         if (final_index_name != curr_index_name) {
1132                 if (!final_index_name) {
1133                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1134                                  get_object_directory(), sha1_to_hex(sha1));
1135                         final_index_name = name;
1136                 }
1137                 if (move_temp_to_file(curr_index_name, final_index_name))
1138                         die("cannot store index file");
1139         } else
1140                 chmod(final_index_name, 0444);
1141
1142         if (!from_stdin) {
1143                 printf("%s\n", sha1_to_hex(sha1));
1144         } else {
1145                 char buf[48];
1146                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1147                                    report, sha1_to_hex(sha1));
1148                 write_or_die(1, buf, len);
1149
1150                 /*
1151                  * Let's just mimic git-unpack-objects here and write
1152                  * the last part of the input buffer to stdout.
1153                  */
1154                 while (input_len) {
1155                         err = xwrite(1, input_buffer + input_offset, input_len);
1156                         if (err <= 0)
1157                                 break;
1158                         input_len -= err;
1159                         input_offset += err;
1160                 }
1161         }
1162 }
1163
1164 static int git_index_pack_config(const char *k, const char *v, void *cb)
1165 {
1166         struct pack_idx_option *opts = cb;
1167
1168         if (!strcmp(k, "pack.indexversion")) {
1169                 opts->version = git_config_int(k, v);
1170                 if (opts->version > 2)
1171                         die("bad pack.indexversion=%"PRIu32, opts->version);
1172                 return 0;
1173         }
1174         if (!strcmp(k, "pack.threads")) {
1175                 nr_threads = git_config_int(k, v);
1176                 if (nr_threads < 0)
1177                         die("invalid number of threads specified (%d)",
1178                             nr_threads);
1179 #ifdef NO_PTHREADS
1180                 if (nr_threads != 1)
1181                         warning("no threads support, ignoring %s", k);
1182                 nr_threads = 1;
1183 #endif
1184                 return 0;
1185         }
1186         return git_default_config(k, v, cb);
1187 }
1188
1189 static int cmp_uint32(const void *a_, const void *b_)
1190 {
1191         uint32_t a = *((uint32_t *)a_);
1192         uint32_t b = *((uint32_t *)b_);
1193
1194         return (a < b) ? -1 : (a != b);
1195 }
1196
1197 static void read_v2_anomalous_offsets(struct packed_git *p,
1198                                       struct pack_idx_option *opts)
1199 {
1200         const uint32_t *idx1, *idx2;
1201         uint32_t i;
1202
1203         /* The address of the 4-byte offset table */
1204         idx1 = (((const uint32_t *)p->index_data)
1205                 + 2 /* 8-byte header */
1206                 + 256 /* fan out */
1207                 + 5 * p->num_objects /* 20-byte SHA-1 table */
1208                 + p->num_objects /* CRC32 table */
1209                 );
1210
1211         /* The address of the 8-byte offset table */
1212         idx2 = idx1 + p->num_objects;
1213
1214         for (i = 0; i < p->num_objects; i++) {
1215                 uint32_t off = ntohl(idx1[i]);
1216                 if (!(off & 0x80000000))
1217                         continue;
1218                 off = off & 0x7fffffff;
1219                 if (idx2[off * 2])
1220                         continue;
1221                 /*
1222                  * The real offset is ntohl(idx2[off * 2]) in high 4
1223                  * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1224                  * octets.  But idx2[off * 2] is Zero!!!
1225                  */
1226                 ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1227                 opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1228         }
1229
1230         if (1 < opts->anomaly_nr)
1231                 qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1232 }
1233
1234 static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1235 {
1236         struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1237
1238         if (!p)
1239                 die("Cannot open existing pack file '%s'", pack_name);
1240         if (open_pack_index(p))
1241                 die("Cannot open existing pack idx file for '%s'", pack_name);
1242
1243         /* Read the attributes from the existing idx file */
1244         opts->version = p->index_version;
1245
1246         if (opts->version == 2)
1247                 read_v2_anomalous_offsets(p, opts);
1248
1249         /*
1250          * Get rid of the idx file as we do not need it anymore.
1251          * NEEDSWORK: extract this bit from free_pack_by_name() in
1252          * sha1_file.c, perhaps?  It shouldn't matter very much as we
1253          * know we haven't installed this pack (hence we never have
1254          * read anything from it).
1255          */
1256         close_pack_index(p);
1257         free(p);
1258 }
1259
1260 static void show_pack_info(int stat_only)
1261 {
1262         int i, baseobjects = nr_objects - nr_deltas;
1263         unsigned long *chain_histogram = NULL;
1264
1265         if (deepest_delta)
1266                 chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1267
1268         for (i = 0; i < nr_objects; i++) {
1269                 struct object_entry *obj = &objects[i];
1270
1271                 if (is_delta_type(obj->type))
1272                         chain_histogram[obj->delta_depth - 1]++;
1273                 if (stat_only)
1274                         continue;
1275                 printf("%s %-6s %lu %lu %"PRIuMAX,
1276                        sha1_to_hex(obj->idx.sha1),
1277                        typename(obj->real_type), obj->size,
1278                        (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1279                        (uintmax_t)obj->idx.offset);
1280                 if (is_delta_type(obj->type)) {
1281                         struct object_entry *bobj = &objects[obj->base_object_no];
1282                         printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1283                 }
1284                 putchar('\n');
1285         }
1286
1287         if (baseobjects)
1288                 printf("non delta: %d object%s\n",
1289                        baseobjects, baseobjects > 1 ? "s" : "");
1290         for (i = 0; i < deepest_delta; i++) {
1291                 if (!chain_histogram[i])
1292                         continue;
1293                 printf("chain length = %d: %lu object%s\n",
1294                        i + 1,
1295                        chain_histogram[i],
1296                        chain_histogram[i] > 1 ? "s" : "");
1297         }
1298 }
1299
1300 int cmd_index_pack(int argc, const char **argv, const char *prefix)
1301 {
1302         int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1303         const char *curr_pack, *curr_index;
1304         const char *index_name = NULL, *pack_name = NULL;
1305         const char *keep_name = NULL, *keep_msg = NULL;
1306         char *index_name_buf = NULL, *keep_name_buf = NULL;
1307         struct pack_idx_entry **idx_objects;
1308         struct pack_idx_option opts;
1309         unsigned char pack_sha1[20];
1310
1311         if (argc == 2 && !strcmp(argv[1], "-h"))
1312                 usage(index_pack_usage);
1313
1314         read_replace_refs = 0;
1315
1316         reset_pack_idx_option(&opts);
1317         git_config(git_index_pack_config, &opts);
1318         if (prefix && chdir(prefix))
1319                 die("Cannot come back to cwd");
1320
1321         for (i = 1; i < argc; i++) {
1322                 const char *arg = argv[i];
1323
1324                 if (*arg == '-') {
1325                         if (!strcmp(arg, "--stdin")) {
1326                                 from_stdin = 1;
1327                         } else if (!strcmp(arg, "--fix-thin")) {
1328                                 fix_thin_pack = 1;
1329                         } else if (!strcmp(arg, "--strict")) {
1330                                 strict = 1;
1331                         } else if (!strcmp(arg, "--verify")) {
1332                                 verify = 1;
1333                         } else if (!strcmp(arg, "--verify-stat")) {
1334                                 verify = 1;
1335                                 stat = 1;
1336                         } else if (!strcmp(arg, "--verify-stat-only")) {
1337                                 verify = 1;
1338                                 stat = 1;
1339                                 stat_only = 1;
1340                         } else if (!strcmp(arg, "--keep")) {
1341                                 keep_msg = "";
1342                         } else if (!prefixcmp(arg, "--keep=")) {
1343                                 keep_msg = arg + 7;
1344                         } else if (!prefixcmp(arg, "--threads=")) {
1345                                 char *end;
1346                                 nr_threads = strtoul(arg+10, &end, 0);
1347                                 if (!arg[10] || *end || nr_threads < 0)
1348                                         usage(index_pack_usage);
1349 #ifdef NO_PTHREADS
1350                                 if (nr_threads != 1)
1351                                         warning("no threads support, "
1352                                                 "ignoring %s", arg);
1353                                 nr_threads = 1;
1354 #endif
1355                         } else if (!prefixcmp(arg, "--pack_header=")) {
1356                                 struct pack_header *hdr;
1357                                 char *c;
1358
1359                                 hdr = (struct pack_header *)input_buffer;
1360                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
1361                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1362                                 if (*c != ',')
1363                                         die("bad %s", arg);
1364                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1365                                 if (*c)
1366                                         die("bad %s", arg);
1367                                 input_len = sizeof(*hdr);
1368                         } else if (!strcmp(arg, "-v")) {
1369                                 verbose = 1;
1370                         } else if (!strcmp(arg, "-o")) {
1371                                 if (index_name || (i+1) >= argc)
1372                                         usage(index_pack_usage);
1373                                 index_name = argv[++i];
1374                         } else if (!prefixcmp(arg, "--index-version=")) {
1375                                 char *c;
1376                                 opts.version = strtoul(arg + 16, &c, 10);
1377                                 if (opts.version > 2)
1378                                         die("bad %s", arg);
1379                                 if (*c == ',')
1380                                         opts.off32_limit = strtoul(c+1, &c, 0);
1381                                 if (*c || opts.off32_limit & 0x80000000)
1382                                         die("bad %s", arg);
1383                         } else
1384                                 usage(index_pack_usage);
1385                         continue;
1386                 }
1387
1388                 if (pack_name)
1389                         usage(index_pack_usage);
1390                 pack_name = arg;
1391         }
1392
1393         if (!pack_name && !from_stdin)
1394                 usage(index_pack_usage);
1395         if (fix_thin_pack && !from_stdin)
1396                 die("--fix-thin cannot be used without --stdin");
1397         if (!index_name && pack_name) {
1398                 int len = strlen(pack_name);
1399                 if (!has_extension(pack_name, ".pack"))
1400                         die("packfile name '%s' does not end with '.pack'",
1401                             pack_name);
1402                 index_name_buf = xmalloc(len);
1403                 memcpy(index_name_buf, pack_name, len - 5);
1404                 strcpy(index_name_buf + len - 5, ".idx");
1405                 index_name = index_name_buf;
1406         }
1407         if (keep_msg && !keep_name && pack_name) {
1408                 int len = strlen(pack_name);
1409                 if (!has_extension(pack_name, ".pack"))
1410                         die("packfile name '%s' does not end with '.pack'",
1411                             pack_name);
1412                 keep_name_buf = xmalloc(len);
1413                 memcpy(keep_name_buf, pack_name, len - 5);
1414                 strcpy(keep_name_buf + len - 5, ".keep");
1415                 keep_name = keep_name_buf;
1416         }
1417         if (verify) {
1418                 if (!index_name)
1419                         die("--verify with no packfile name given");
1420                 read_idx_option(&opts, index_name);
1421                 opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1422         }
1423         if (strict)
1424                 opts.flags |= WRITE_IDX_STRICT;
1425
1426 #ifndef NO_PTHREADS
1427         if (!nr_threads) {
1428                 nr_threads = online_cpus();
1429                 /* An experiment showed that more threads does not mean faster */
1430                 if (nr_threads > 3)
1431                         nr_threads = 3;
1432         }
1433 #endif
1434
1435         curr_pack = open_pack_file(pack_name);
1436         parse_pack_header();
1437         objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1438         deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1439         parse_pack_objects(pack_sha1);
1440         resolve_deltas();
1441         conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1442         free(deltas);
1443         if (strict)
1444                 check_objects();
1445
1446         if (stat)
1447                 show_pack_info(stat_only);
1448
1449         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1450         for (i = 0; i < nr_objects; i++)
1451                 idx_objects[i] = &objects[i].idx;
1452         curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1453         free(idx_objects);
1454
1455         if (!verify)
1456                 final(pack_name, curr_pack,
1457                       index_name, curr_index,
1458                       keep_name, keep_msg,
1459                       pack_sha1);
1460         else
1461                 close(input_fd);
1462         free(objects);
1463         free(index_name_buf);
1464         free(keep_name_buf);
1465         if (pack_name == NULL)
1466                 free((void *) curr_pack);
1467         if (index_name == NULL)
1468                 free((void *) curr_index);
1469
1470         return 0;
1471 }